This invention generally relates to electrical connectors, and more specifically to a multi-position electrical connector.
Multi-position electrical connectors or switches are often used to alter the current flow path through an electric apparatus or device and simultaneously to connect the apparatus to one of a plurality of power supplies. For example, many electric motors may be driven by different power supplies having different electric voltages such as either a 220 volt power source or a 440 volt power source. Typically, these motors include multiple windings, where each motor winding has a pair of winding sections. A multi-position electrical connector or switch is used to connect the sections of individual windings in series when the motor is connected to a first power source such as the 440 volt power supply, and to connect the sections of individual windings in parallel when the motor is connected to a second power supply such as the 220 volt power source.
Motors of the general type described above are often used with refrigeration machines employed to cool or condition the interior of a transportable container unit. To elaborate, during the course of its lifetime, a transport container unit may pass through numerous countries and regions in the world. In certain areas the principle--often the only--electric energy source provides a 440 volt current, while in other areas the primary--and again often the only--electric energy source provides a 220 volt current. Consequently, refrigeration machines for transport container units are often provided with an electric motor which may be driven by either of these energy sources.
Heretofore, rotary switches, wherein rotation of a knob or dial moves a plurality of conductive members into and out of electric engagement with other conductive members, have usually been used to switch the motor winding sections between series and parallel operation and to connect the motor to a selected one of a plurality of power supplies. Rotary switches, however, typically include a relatively large number of parts such as springs, pins, and detents in order to insure that, as the switch changes positions, the appropriate conductive members are brought into secure electrical contact. Because of this large number of parts, rotary switches are relatively expensive to produce; and as a result of this, efforts have been made to design an electrical connector or switch which will achieve the same results as a rotary switch but which is less expensive to manufacture and assemble.
These efforts have produced a relatively simple and inexpensive, unique electrical connector. The connector comprises a plug including a plurality of blades and a socket defining a plurality of receptacles for receiving the blades. The socket has two longitudinally spaced apart, electrically engaging positions. In the first position, the plug and socket engage to connect sections of individual motor windings of a motor in parallel and to connect the motor to a first voltage source. In the second position, the plug and socket engage to connect the sections of individual motor windings in series and to connect the motor to a second voltage source. When the plug and socket engage, clips or grips secured within the receptacles of the socket securely engage individual blades of the plug to hold the plug and socket together, and preferably the plug and socket are tightly held together. While this essentially eliminates the possibility that the plug and socket will accidently or inadvertently come apart, it also makes it difficult to move the socket between its two positions, especially solely by hand.